The success of Windows RT, and to a lesser extent Windows 8, will hinge on the quality and quantity of apps in the Windows Store next month, analysts said today.

And they don't like what they've seen so far.

"History shows that for consumers, the first impression is the one that sticks," said Patrick Moorhead, principal analyst with Moor Insights & Strategy, referring to app availability. Yet, just weeks before the Oct. 26 launch of Windows 8 and Windows RT, the Windows Store inventory is not only light, but doesn't include many of the apps consumers see as must-haves, he continued.

Moorhead pointed out several recent tablet failures, including Hewlett-Packard's TouchPad and RIM's BlackBerry PlayBook, and said that one commonality was their lack of high-quality apps. Microsoft risks following in their footsteps if it can't demonstrate its app store is well-stocked at launch.

"You get just one chance with consumers," Moorhead argued. "Microsoft is commercial first, consumer second. With the commercial market, you can roll out and then grow [application availability]. But in the consumer market, it has to succeed immediately."

Other experts also worried about the app situation.

"At the end of the day, it's all going to come down to the Windows Store," said Michael Cherry, an analyst with Directions on Microsoft. "There's been so much wailing and gnashing of teeth over Windows 8, most of it around the ["Modern"] interface, but over time I'm adapting to the UI. But here's what my big problem is as of today: I have yet to find an app that I just have to have."

The Windows Store is the only distribution center for Windows 8 and Windows RT apps written for what Microsoft calls the "Modern" interface, the tile-based environment borrowed from Windows Phone. Like Apple's iOS App Store and its OS X Mac App Store, the Windows Store is curated -- Microsoft reviews each submission and is the final arbiter of what can be sold or given way for free.

There are currently just over 1,000 apps in the Windows Store, a far cry from the more than 200,000 in Apple's App Store written specifically for the iPad.

"Apps are certainly critical," said Michael Silver, of Gartner, who included a robust app store as one of a handful of must-dos for Microsoft. If the Windows Store isn't populated by enough apps, or at least enough of the top-selling apps available on other platforms -- what Silver called a "critical mass" -- Microsoft will have its work cut out for it.

"If they don't [have the right apps], Windows 8 and Windows RT will be challenged in the consumer market," said Silver. "But I wouldn't count them out if they don't get it right the first time. They'll just spend another half billion dollars on marketing, and risk [Windows 8/RT] getting a bad reputation, like Vista did. So it's a lot easier if they get it right the first time."

Although a lack of apps may affect Windows 8 less than Windows RT, since the former can run traditional, or "legacy" apps on the Windows 7-style desktop, a lightly-stocked Windows Store could stymie sales of touch-based PCs, tablets and so-called "convertibles" -- hardware that combines elements of both tablets and notebooks -- powered by Windows 8.

"Windows 8 is going to do just fine, particularly because consumers won't have a choice," said Moorhead. "But the hardware being trumpeted is not as inexpensive as a tablet, and more expensive than a traditional notebook. People are going to pay more for that touch screen, and they're going to want to know what kind of apps they can run on it."

Cherry agreed.

"If there's little you can do with [a new touch-enabled PC], it will naturally throttle the market," Cherry said.